Nanoparticle-based biotechnology is quickly heading to the forefront of drug delivery, diagnosis and other areas. One of the largest obstacles to these applications is nonspecific protein adsorption, which can result in cellular uptake, nanoparticle aggregation, immune system response and other disastrous problems for in vivo applications. This lack of a versatile effective nonfouling material is thus a crucial issue for many nanoparticle-based biomedical applications. Poly(ethylene glycol) (PEG) and oligo(ethylene glycol) (OEG) are the most commonly studied nonfouling materials. However, PEG or OEG can auto-oxidize rapidly in the presence of oxygen and transition metal ions. Another class of nonfouling materials is based on phosphorylcholine (PC), but these are harder to synthesize. In addition to fouling resistance, many biomedical applications require a functionalizable surface. This is necessary to immobilize a bio-recognition element for targeting specific disease areas or selectively interacting with cells or biomolecules. There are few reports about directly functionalizing PEG surfaces. However, these involve complex reactions.
Although performance of low fouling materials and coatings has been demonstrated for relative expansive macroscopic surfaces, surface chemistries are still challenging for nanoparticles used in diagnostics and therapeutics, particularly in complex media such as blood.
Therefore, a need exists for low fouling materials and coatings for application to nanoparticles, particularly in complex media. The present invention seeks to fulfill this need and provides further related advantages.